I will first write a sequence of commands which I want to run

echo <some_input> | <some_command> > temp.dat & pid=$!
sleep 5
kill -INT "$pid"

The above is working perfectly fine when i run it one by one from bash shell, and the contents in the temp.dat file is exactly what I want. But, when I create a bash script containing the same set of commands, I am getting nothing in the temp.dat file.

Now, I'll mention why I'm writing those commands in such a way:

1. <some_command> asks for an input, that's why I'm piping <some_input>
2. I want the output of that command in a separate file, that's why I've redirected the output.
3. I want to kill the command by sending SIGINT signal after some time.

I've tried running an interactive shell by writing #!/bin/bash -i in the first line of the shell script, but it's not working.

Any alternate method to achieve the same results will be appreciated.

• Update: <some_command> is also invoking a python script, but I don't think that this will cause it to behave differently.
• Update2: python script was the only cause of that different behavior.

CodePudding user response：

One likely cause here is that your Python process may not be flushing stdout within the allowed five seconds of runtime.

export PYTHONUNBUFFERED=1

...will cause content to be promptly written, rather than waiting for process exit / file close / amount of buffered content to reach a level sufficient to justify the overhead of a flush operation.

CodePudding user response：

will this work for you?

read -p "Input Data : " inputdata ; echo $inputdata > temp.data ; sleep 5; exit

obvs

#!/usr/bin/env bash 

read -p "Input Data : " inputdata
echo $inputdata > temp.data
sleep 5

should work as a script

to suit :D

#!/usr/bin/env bash 

read -p "Input Data : " inputdata
<code you write eg echo $inputdata> > temp.data
sleep 5